Shad Laws

Hello-

Just how much does having staggered wheel sizes (say 8.5" in front and 9.5" in rear, for the sake of argument) change the handling characteristics of the FD at the limits? What about bigger rims and, consequently, shorter sidewalls?

My car is more-or-less stock (Tokico shocks with a strut tower on a '93 suspension... with the factory bigger rear anti-sway bar). Right now with stock 16x8's all around, it's nice and tossable - it's really easy to control turns with the throttle. It also gives me plenty of warning at the limits. With this setup, it's a lot of fun and it feels very intuitive - there's plenty o' feedback as to what's going on. Twisties are a blast. I like 2nd-gear twisties a lot... I don't want to compromise the ability to do them well.

As my tires are wearing down, part of me wants to get bigger wheels. Will having 17" or 18" rims be nice, or just make it harder to maneuver at the limits with less feedback? What about widths - would having wider all around be nice, or does staggered feel better? Just how much understeer do you get... does it feel better or just more sluggish? Also, how much worse do rough roads become with bigger wheels and shorter sidewalls?

Right now, here are my potential thoughts:
- stock 16x8, 245/45/16 Toyo T1-R (not T1-S... the new T1-R that you can import from Canada)
- aftermarket 17x9, 255/40/17 Michelin Pilot Sport PS2
- aftermarket 18x8.5 and 18x9.5 staggered, Michelin Pilot Sport PS2 again
- any other combination of the above... you get the idea :-)

I've tried to search on this, but haven't found a "direct" answer to the question (if there is a thread I missed, by all means please post the link :-).

Thanks in advance!

Take care,
Shad

Shad Laws

<bumpity bump>

FlameThrowingRotary

i'm running 18x8.5 front and 9.5 rear with 235/40's and 275/35 and my car handle's pretty well, I do have tokico's and tein springs with strut bars and I managed to bend the hell out of my sway bar mounts lol. so yeah it handle's pretty good staggard, I like it better cause the *** end is a little more planted. the more rubber on the road the better in my opinion but 17's are a better choice for racing just depends on what you want

7racer

Look up Howard Colemans post. They have been answered pretty well.

But in General having a staggered setup will induce understeer compared to the balanced setup of the stock system. In the past it use to be that everyone tried to keep the balance as stock as possible. SleepR1 was a big proponent of this. Not only was this great for "balance" but also nice in the regards of being able to rotate tires.

More recently a very avid and knowledgable suspension guru, Howard Coleman, runs a staggered setup like described. If I remember correctly he runs 18x8.5f and 18x10 rear. His contention is that the understeer induced by the staggered setup is not a big issue and that for road racing is fine.

In regards to your other questions. It really is subjective. Going with shorter sidewalls will give the car a more "harsh" ride. I have JIC's which have very high spring rates but they don't seem to bother me. To tell you the truth my car greatly exceeds my current driving ability. I think if you go with the staggered 18 setup and springs that Howard recommends that you will have a nicely balanced FD that you can easy grow with on the track. If your tight on money just upgrade the springs as the FD is already a great car. Just as an example, DamonB with his stock car, runs rings around me during SCCA autox events with my previously modified car.

Donovan

If you have an adjustable suspension (coilovers,adjustable shocks,different sway bars,etc.) you can dial in the over/understeer to compensate for the wider rear tires. If you have more rubber in the back you need to dial in oversteer. Most of us that own these cars arn't good enough to reach the full potential of the car anyway and I feel it's safer for my driving habits to keep the rear end planted with bigger tires as I have more power than a stock car.

FlameThrowingRotary

yeah what he said lol. like i said before with my setup i didn't notice any understeer but I dont track the car either. for everyday driving I have more than enough grip up front it's the rear end I can't keep down until 3rd.

Shad Laws

Hello-

I know very well how suspension can be used to setup a car... been there and done that. But, my car isn't a track car... it's a daily driver that I enjoy taking on backroad twisties, including some rough roads. For this, the stock suspension is an awfully good compromise between cutting edge performance and reality... Mazda wasn't stupid when they designed the car :-).

However, trends in tires and wheels have definately changed since 1993. Back then, the FD came with larger tires than a 911. Now, well, not so much :-). My question is how much the balance of the car will be changed if all else is kept the same. Having stiffer tires will mean smaller slip angles, which can lead to a more responsive car that may be more tricky to manipulate at its limits, but I'm not sure how much of each of those traits you get. I'm also not sure how the FD deals with road irregularities with stiffer tires/wheels. Furthermore, I'm not sure if having a staggered setup means that the car feels more "secure" (i.e. riding on rails) or just more "sluggish" (i.e. needs large inputs to turn, harder to steer with both axles easily, etc.). I'd like feedback on these questions from folks that understand what I'm talking about and have done some experimentation of their own already...

Thanks!

Take care,
Shad

FlameThrowingRotary

well here's my honest opinion
stock wheels/tires=ghey
nice rims with some good meats= faster car and better handling

and like I said early I bent the hell out of my sway bar mounts on staggered set up, seams like it rides on rails a lot better now then it did. and who cares about ride quality. If you do then sell your 7 and get a caddy. I like to feel the bumps in the road

Shad Laws

Hello-

1. I'm asking about the handling of the car, not the gayness of it :-).
2. I seriously doubt that bigger wheels and tires make a faster car :-). In fact, to be really technical, bigger tires create more rolling resistance and slow the car down... but that's a small effect and beside the point.

I never said ride quality. I asked about handing on rough roads. I don't care about how smooth it feels... what I care about is the ability for my wheels/tires/suspension to maintain traction on the not-so-nicely-paved backroad twisty as I carve through the turns. The technical term for this is road-holding ability. Getting more of it does NOT necessary mean giant springs...

Does anyone out there have answers to the actual questions I'm asking? Thanks!

Take care,
Shad

FlameThrowingRotary

what I was meaing with bigger tires is that yea I know more mass and all creates more resitance but the trade off of traction more than makes up for it. stock wheels and tires i couldnt get on it till 4th or it'd burn all through 3rd now I just have to feather 1st and 2nd and can lay in on 3rd and my car is a lot faster now with more traction and more rolling mass. also waco tx has the worst roads in the US hands down, i've been on smoother country roads then some of the streets here and with my setup, adj tokico and tein drop springs I don't bounce around it stays pretty planted in the turns with the bumps. I'm just saying you'll be a lot happier with wider tires. what they add to rotational mass is nothing compared to how much better they grip and the amount of control you gain over a 225/50 tire.

rynberg

RIGHT! With a stock twin'd car with your mods? What are you running, Goodyear Aquatreds or something?


Shad, here's a link to my review of the exact situation you are looking at -- going from the stockers to 18x8.5/18x9.5 with both track and street comments.

https://www.rx7club.com/showthread.p...ighlight=enkei

You'll notice in my review, I stated that staying with the stockers was possibly more fun for street driving (or at least staying with symmetrical sizing). I also definitely felt the increased unsprung mass in my car, and I have a fairly light aftermarket 18" setup. Feel free to ask me anymore questions either here or via PM.

Tad

imo,
you can't really see the LIMITS of your car on the streets anyway,
so just go with something that'll feel good...

get the widest wheels/tires you can, wider the better,
yeah don't try to stagger them too much I think...

And in your case, sounds like you might want a 17" wheel so ur tires sidewall isn't too thin/stiff.

Dane

OK, this may get some flames, but staggered wheels / tires on stock FD's are for cosmetic reasons. The exception is when vehicles have a rear weight bias...then it is necessary (ie NSX, MR2, 911, etc). Another scenario are RWD cars that have so much torque they need a little more rubber for traction (300ZX / Supra Turbo).
On a car that is 50/50 like the FD, there is no reason other than looks to stagger if running the stock two hundred and something hp / torque , and IMO, the selling point of a street driven FD is the handling balance anyway.
I agree with what one person already said...Mazda wasn't stupid, and could have easily staggered the assemblies if they needed / wanted (it was fairly common at the time).
The R1 suspension pulled incredible g's (as high as .99 C/D 92') with stock suspension, and only 225's - yet you can check out many road tests of aftermarket tuner versions where they actually lost g's and slalom times by adding much bigger (and often staggered) wheels and tires, different springs, bushings, etc. Suspension geometry is a black art, and more is NOT necessarily better when you are getting into relatively complex suspension designs like the FD.
I am sure I may get a flame or two, but road tests back this up which use extremely high dollar equipment, professional test drivers, true test tracks...and all data ran through calibration software...or you can belive some guy on the board that said his car is much stickier with their own choices of setup (and NO supercray computer)...your call.
On the other hand, staggered wheels sure look bad ***

93silverbullet

iTrader: (7)

While this statement is true, (Mazda undoubtly spent hugh sums of money designing and testing the suspension geometry of the FD) Mazda did in fact stagger the sizes on the 99 spec cars with 17" rims. Front: 17"x8" with 235/45-17; Rear: 17"x8 1/2" with 255/40/17. This must have been done with eye towards further improving the handling qualities of the car... not just for astetic reasons.

rynberg

No, they're not. I'm guessing you haven't had your FD on too many road courses? I find the car much easier to apply power out of the corners with ON THE TRACK with staggered setup. I also said above that the stock setup is more fun on the street. But nimbleness is not the most important factor on most tracks -- putting the power down through corners is. A large percentage of the experienced FD track guys run staggered setups, not because they look cool, but because they are better/faster/more comfortable on the track with them.

EDIT: Oh, and I hate to break it to you, but Mazda started running staggered setups on FDs after 1996 or so.

gfelber

Right on!

I've tracked my car several years with same sized footprint front and rear. After going with a stagger (285 front, 305 rear), I was shocked at the improvement. Oversteer was much more progressive and the car is easier to catch at or near the limit. Much easier transitions to full throttle as well.

Even on a stock powered FD the results are similar. I believe Mazda set their fastest laps using the post 1996, staggered setup- that's why they went into production with it. Recall the famous Porsche 911 RS CS *** whipping at Bathurst? That was using staggered setup on the RX-7 SP1 (235 front, 255 rear).

Gene

Gene

rx713bt

iTrader: (4)

I'm running staggered setup for the street and track and it's a much better setup. With the stock R1 setup, it oversteers too easily and I think that's why there are so many noobie with wrecked FDs. I've added a bigger front sway bar to complement the bigger R1 rear bar. I still get a little oversteer cause I have shitty tires on the rear compared to the front.

alberto_mg

Here is another good link with lots of info from some of the forum "elders". Good stuff.

https://www.rx7club.com/showthread.p...eutral+balance

You can always go for the "SleepR1" fitment

Shad Laws

Hey guys-

Thanks for some great responses! Another question, though... what was the non-staggered setup you started with? I'm trying to figure out how much of the benefits you're talking about are from simply going with wider, stiffer tires vs. actually staggering their sizes. Has anyone done something similar to 17x9 w/ 255/40/17 (Copyright SleepR1. All Rights Reserved. :-) and compared it back-to-back with a staggered setup, or have most folks just gone straight from stock to a big, stiff, and staggered setup? Thanks!

Take care,
Shad

alberto_mg

I'll make a generality here that I think most people make the jump to big, stiff and staggered and then play with sizes depending on how happy they are with their results. The track guys (like SleepR1, maxcooper, gfelber, flyinfritz etc etc) that go through tires often will experiment more with sizes. Us regular guys will get a few years out of our tires and not experiment with sizes as often.

Overall, wider in the rear compared to same size all around will generally yield more understeer vs being more neutral. Some people will like that or need that depending on how much power they are putting out.

FWIW, I've driven the SleepR1 fitment and it felt natural. On my old TurboII, I did not enjoy the staggered fitment at all but that is a different car. I'm a big fan of the SleepR1 fitment for my driving tastes

Rip

Shad?

Is this the Shad Laws of LN engineering? If so, it's been a long time. And I didn't think I'd run into you here. Hope things are well.

Rip

rynberg

Well, I'm pretty sure I remember Manny saying that he felt much more comfortable on the track with his staggered setup (17x8.5, 17x9.5 SSR Comps) than with his symmetrical street setup (17x9). I think in the last year or so, he was just running his "street setup" on the track. Not sure about that though, Manny has apparently moved on and is no longer posting here...

gfelber

That''s true. A lot of this comes down to driving style,suspension setup, and the track. I like the staggered setup when tracking a car with decent power (> 350 RWHP), but I should mention that, if one choses to go this route, you still need a good size tire up front to slow the car down.

I was pretty happy with the symmetical setup and many still swear by it. The biggest drawback for me was running the 285-30-18 rear which has a very short sidewall and had a tendency toward snap oversteer and poor breakaway characteristics. I used to run 17x10 with 275-40s all around and liked the handling characteristics better at the rear (though turn-in is better on 285-30-18 up front) . That's wwhy I went with a 285 up front and a taller sidewall/wider 305 in the rear.

FWIW, one of the fastest, non-professionally raced third gens I've seen (US only) runs a symmetrical setup.

Gene

Dane

I knew that would stirr a bunch of people up, particularly since that is the fad right now...I probably should have stayed out of this one
But keep in mind that I was answering the original question the guy had...he wanted to know about a street driven car, and a stock one at that, I believe. Everyone seems to jump straight to mentioning their track experience or things of this nature.
Two things I have noticed is that people on forums almost always feel they know more than the manufacturer of a vehicle, and second guess descisions that were made, and always feels more is better (the two things I pretty much argued against),so I should have known better, once again.
I still feel that a street driven FD with stock horsepower is better off handling wise with a balanced setup, as was what the engineers / designers thought originally too...I never said anything about track use and stuff like that (other than saying the many tuner versions are slower around the track than the R1, even with 20K extra in parts - ie P.F. RX7).
Maybe they had something different in mind later in Japan for the way they wanted the car to feel...sure, but they have the engineering and design to change to a staggered setup.
A regular person (us) switching tire sizes around with a stock suspension which is highly TUNED for the same tires all around and / or mixing and matching suspension parts, therefore altering the geometry IS NOT the same as what Mazda did.
However, if you feel that they made for a better design by stagering in 96 or 99 or whatever, you would have to swap to the newer setup to get the same thing...obviously. The other option would be to get a setup from a reputable tuner, and rely on their R/D.
Or you can simply guess what you think is best and swear you have improved on their design without a single piece of test equipment, research or design team. See my point...if not, then please no flames...send them to Mazda.

rynberg

Dane, you make good points, but you seem to be ignoring the fact that I have personal experience with both setups and how they drive, both on the street and the track. I know that I feel more comfortable driving the car harder on the track with the staggered setup and therefore I GO FASTER. Of course I am altering Mazda's original suspension balance, I stated that in my earlier review and posts. However, I drive FASTER with this balance, and that's a proven fact using my lap times. I also state that the car does, indeed, feel better on the street with the stock setup (or at least symmetrical).

Perhaps you're only addressing those owners who spend thousands of dollars on suspension and wheel/tire upgrades and never see the track, in that case, I agree with what you are saying. But to discount the thousands of track hours by several FD owners, when you don't have that experience yourself, I think you're losing the forest for the trees....